According to the prior art, the preparation required to reuse liposuctioned material involves the separation of the vital cell component to be re-injected from the waste material composed of anesthetic liquid or biological fluids (serum or blood) from cell debris and oil resulting from the rupture of suctioned adipocytes.
Such separation may occur within the syringe that is used for withdrawal, or in special containers, essentially in three manners:
by settling: the materials separate due to differences in density under gravity,
by centrifugation: the materials separate due to differences in density under the effect of a centrifugal force,
by washing: the lipoaspirate is placed in a thin-mesh strainer and washed, generally with a saline, that may be progressively replaced or not.
According to the best known technique (Coleman lipostructure), the syringes containing the lipoaspirate are closed at the bottom by a luer-lock cap, and are placed in a centrifuge for separating the liquid phase from the solid biological material.
Before using the biological material so obtained, the anesthetic and biological liquids left on the bottom of the syringe after centrifugation must be manually drained by removing the luer-lock cap from the syringe and causing them to flow out by gravity, whereas the cell fragments and oil resulting from the breaking of the cell walls of adipocytes lie on the cell material to be transplanted and are removed in an incomplete and rudimentary manner, using gauzes that partially absorb the excess oil and often make the last part of the suctioned material unusable.
The above described technique suffers from a number of drawbacks.
First, the step of suction and separation by centrifugation causes a considerable amount of adipocytes to break and release a significant amount of oil, which cannot completely removed with the Coleman technique, and makes a significant portion of the lipoaspirate unusable, that is, the portion of cell material that, after centrifugation, is located on the upper part of the syringe barrel, in contact with oil, and hence is contaminated by said oil.
This is because the presence of oil in the biological filler to be injected increases the risk of infections and rejections and causes increased inflammations.
Furthermore, the above described process involves multiple contacts of the liposuctioned material with surfaces of various types of instruments, as well as long-time contact with air in a potentially non-sterile environment, whereby use thereof in an operating room is recommended.
A technique is also known but rarely used, which involves mechanical fragmentation of the suctioned cell agglomerate using a blender, whose cutting blades separate fat lobules and provide an injectable cell suspension.
This fragmentation technique has many drawbacks.
First, the fragmentation step, which is followed by centrifugation, causes a considerable amount of adipocytes to break, which causes more than half of the liposuctioned material to be unusable for later aesthetic treatments. As a direct result, an increased number of liposuction sessions are required to compensate for this loss of material occurring during preparation of the material to be transplanted, with increased discomfort for patients.
Furthermore, the quantity of usable cell suspension that can be obtained using the above described procedure and devices largely depends on the skill of the health care staff in setting the speed and operating time parameters of the blender and the centrifuge and on the conditions of the instruments: an excessive rotation speed of the blades or the use, for example, of a blender with poorly cutting blades does not cause separation of fat lobules, but rather the mechanical break of the cell walls of a large amount of adipocytes, which involves oil formation and makes the cell suspension unusable, in addition to requiring accurate separation of the cell fragments and oil from the suspension. This is because the presence of oil in the biological filler to be injected increases the risk of infections and rejections.
Furthermore, the above described process involves multiple contacts of the liposuctioned material with surfaces of various types of instruments, as well as some contact with air in a non perfectly sterile environment, as is the case of doctor's offices. Since the material is of biological nature, extended contact with air or with multiple instruments, that may even not be perfectly sterile, increases the risk of bacterial or viral contamination, and may jeopardize treatment results.
The technique that involves washing through a strainer also has certain drawbacks.
Particularly the strainer net may easily become clogged with the liposuctioned material, which requires a manual action to remove fat from the meshes, thereby slowing down the preparation process and especially increasing the risk of contamination of the material to be injected.
The use of a simple strainer does not allow the liposuctioned material to be constantly maintained in a closed and perfectly sterile environment throughout the preparation process, i.e. from the liposuction step to the injection step.
Patent documents are known which disclose cell isolating devices.
The international application WO 2009/073724 discloses a method and an apparatus for isolating cells from lipoaspirate.
Particularly, it discloses a method for separating the adipocyte and oil fraction from the non-fat cell fraction in a lipoaspirate.
In order to obtain lipids and adipocytes that float on a cell solution of interest and other small cells within a container defined as “separation chamber”, the adipose tissue is placed in a digestion chamber, and forced through a filter and through a head having pores into said “chamber”.
The steps of washing the tissue, removing excess liquids, enzymatic digestion, antibiotic addition and cell selection may occur in a container defined as “digestion chamber”. The digestion chamber may contain a filter that retains the tissue but allows the passage of dissociated cells and fluids. An aqueous emulsion containing adipocyte lipids is formed in this chamber.
The dissociated material in the digestion chamber may pass through a dispersing filter with pores smaller than the pores on the dispersing head contained in the first “separation chamber”. This filter 115 is used to prevent clogging of the pores of the dispersing head.
In the “separation chamber” the lipids and adipocytes are separated from the cell population.
The device provides a cell population from a tissue without using the centrifuge but by forcing the solution through filters with pores of various sizes.
Said device is particularly complex in terms of construction, as shown in the figures.
Furthermore, the many passages of the organic material through chambers and filters extend the duration of the method, and expose the organic material to contamination risks.
Also, the complexity of the method and device make them unsuitable for use, for instance, in out-patient environments, which require quick preparation of injectable material from lipoaspirate and quick performance of face and body defect correction without the assistance of particularly specialized staff.
Furthermore, in this method, emulsions are formed using chemicals and not only through the use of mechanical means and forces.
US Application 2007/0274960 discloses a method of preparing a stem cell-containing composition. In order to prepare a stem cell population, in certain embodiments the liposuctioned adipose tissue is physically treated, i.e. cut or minced into smaller pieces, and undergoes enzymatic treatment, which facilitates release of the cells of interest from the other tissue components.
Therefore US 2007/0274960 allows the adipose tissue to be divided into smaller pieces by forcing it through an array of screens, to obtain smaller portions of uniform sizes, that can undergo enzymatic treatment in a more uniform manner, thereby providing a quicker release of stem cells and reducing the contact time between the released cells and the enzyme solution.
According to this patent, an emulsion of adipose tissue may be prepared using a perfluorocarbon solution, which emulsion is separable from the stem cells of interest.
The patent does not include the preparation of an emulsion of liquids that can be mechanically separated from lipid cells or small cell agglomerates.
The container that contains the cutting means cannot be also used for injecting adipose tissue into a patient. U.S. Pat. No. 6,020,196 discloses a method for collecting microvascular endothelial cells.
The patent describes a method of treating suctioned adipose tissue, which adipose tissue, suctioned by a syringe with a cannula having apertures of such a size as to minimize stresses on cell components and to obtain a homogeneous adipose tissue, is forced from one syringe to another through a filter (74) located between the suction ports of the two syringes.
By pulling the pistons of the syringes, the suctioned adipose tissue is homogenized by being forced through the filter from one syringe to another.
A lower viscosity of the suctioned material allows easier removal of the contaminants and improved digestion of the sample, for obtaining endothelial cells.
The method as disclosed in this patent suffers from certain drawbacks that make it unsuitable for use in the preparation of injectable fat, because:
the filter may become clogged by the adipose tissue: the filter-holding device forms a restriction in the flow line from one syringe to the other; the clogged filter obstructs the passage of adipose tissue from one syringe to the other and requires disconnection of the syringe and replacement of the filter to continue adipose tissue washing; due to these steps, the preparation of an emulsion of solid and liquid components becomes difficult and time-consuming and the organic material is exposed to contamination;
the passage through the filter meshes for disintegration of the connective tissue also leads to the break of adipocytes, with formation of excess oil and the need for a later accurate separation of intact fat cells from oil.
U.S. Pat. No. 6,020,196 provides a homogenate from which endothelial cells may be extracted with the addition of collagenase and centrifugation, hence through the combination of chemical and physical actions. The patent does not involve the formation of an emulsion of liquid components upon which lipid cells or small agglomerates of lipid cells obtained from liposuctioned adipose tissue may float, which cells are directly injectable, after appropriate treatment, into a patient, without requiring particular sterile conditions of the environments, e.g. without requiring a perfectly sterile operating room.
U.S. Pat. No. 6,020,196 does not involve the possibility of providing a single device that, through a few simple treatment steps, allows preparation of the liposuctioned material and collection and temporary storage of fat, until reinjection.
Patent application US 2003/0100105 discloses an apparatus for extracting cells from organs. The apparatus includes a digestion chamber containing the organ and protease, and agitation means, such as balls having at least one cavity, which balls only act upon the organ.